Mercurial > hg > svcore
view data/model/PowerOfSqrtTwoZoomConstraint.cpp @ 1689:d7b04b0ed056 single-point
Build fix for older Qt
author | Chris Cannam |
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date | Fri, 05 Apr 2019 13:40:08 +0100 |
parents | 05c3fbaec8ea |
children |
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/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */ /* Sonic Visualiser An audio file viewer and annotation editor. Centre for Digital Music, Queen Mary, University of London. This file copyright 2006 Chris Cannam. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. See the file COPYING included with this distribution for more information. */ #include "PowerOfSqrtTwoZoomConstraint.h" #include <iostream> #include <cmath> #include "base/Debug.h" ZoomLevel PowerOfSqrtTwoZoomConstraint::getNearestZoomLevel(ZoomLevel requested, RoundingDirection dir) const { int type, power; int blockSize; if (requested.zone == ZoomLevel::FramesPerPixel) { blockSize = getNearestBlockSize(requested.level, type, power, dir); return { requested.zone, blockSize }; } else { RoundingDirection opposite = dir; if (dir == RoundUp) opposite = RoundDown; else if (dir == RoundDown) opposite = RoundUp; blockSize = getNearestBlockSize(requested.level, type, power, opposite); if (blockSize > getMinZoomLevel().level) { blockSize = getMinZoomLevel().level; } if (blockSize == 1) { return { ZoomLevel::FramesPerPixel, 1 }; } else { return { requested.zone, blockSize }; } } } int PowerOfSqrtTwoZoomConstraint::getNearestBlockSize(int blockSize, int &type, int &power, RoundingDirection dir) const { // SVCERR << "given " << blockSize << endl; int minCachePower = getMinCachePower(); if (blockSize < (1 << minCachePower)) { type = -1; power = 0; float val = 1.0, prevVal = 1.0; while (val + 0.01 < blockSize) { prevVal = val; val *= sqrtf(2.f); } int rval = int(val + 0.01f); // SVCERR << "got val = " << val << ", rval = " << rval << ", prevVal = " << prevVal << endl; if (rval != blockSize && dir != RoundUp) { if (dir == RoundDown) { rval = int(prevVal + 0.01f); } else if (val - float(blockSize) < float(blockSize) - prevVal) { rval = int(val + 0.01f); } else { rval = int(prevVal + 0.01); } } // SVCERR << "returning " << rval << endl; return rval; } int prevBase = (1 << minCachePower); int prevPower = minCachePower; int prevType = 0; int result = 0; for (unsigned int i = 0; ; ++i) { power = minCachePower + i/2; type = i % 2; int base; if (type == 0) { base = (1 << power); } else { base = (((unsigned int)((1 << minCachePower) * sqrt(2.) + 0.01)) << (power - minCachePower)); } // SVCERR << "Testing base " << base << " (i = " << i << ", power = " << power << ", type = " << type << ")" << endl; if (base == blockSize) { result = base; // SVCERR << "Equal, accepting" << endl; break; } if (base > blockSize) { if (dir == RoundNearest) { if (base - blockSize < blockSize - prevBase) { dir = RoundUp; // SVCERR << "Closer to " << base << " than " << prevBase // << ", rounding up" << endl; } else { dir = RoundDown; // SVCERR << "Closer to " << prevBase << " than " << base // << ", rounding down" << endl; } } if (dir == RoundUp) { result = base; break; } else { type = prevType; power = prevPower; result = prevBase; break; } } prevType = type; prevPower = power; prevBase = base; } if (result > getMaxZoomLevel().level) { result = getMaxZoomLevel().level; } // SVCERR << "Returning result " << result << endl; return result; }